The invention relates to a method of manufacturing a radiation-emitting semiconductor diode whereby a sacrificial layer comprising a polymer is provided on a first side face of a semiconductor body which contains at least one radiation-emitting semiconductor diode, a coating is subsequently provided on the first side face and on a second side face of the semiconductor body which encloses an angle with the first side face and which forms an exit face for the radiation to be generated by the diode, after which the first side face is divested of the sacrificial layer and of the portion of the coating situated thereon through etching of the sacrificial layer.
A radiation-emitting semiconductor diode thus manufactured has an exit face for radiation which is provided with a coating, such as a layer of high or low reflectivity or a passivating layer, also called a mirror coating in the case of a laser diode. Such (laser) diodes are suitable for many applications such as CD (=Compact DIE), DOR (=Digital Optical Recording), bar code readers and systems for glass fiber communication.
A method of the kind mentioned in the opening paragraph is known from JP(A) 61-70780 published in Patent Abstracts of Japan, vol. 10, no. 240, 19th Aug. 1986. According to the usual methods of providing a coating, such as sputtering, vapor deposition and the like, the coating is provided also on surfaces other than the desired surface of the semiconductor body. Thanks to the use of the sacrificial layer, which comprises a polyimide resin in the known method, a surface of the semiconductor body where no coating is desired, for example the upper surface, is freed from the portion of the coating which has deposited on that surface.
A disadvantage of the known method is that laser diodes manufactured thereby have a starting current which is higher than expected or--in particular in the case of high-power laser diodes--have a comparatively low maximum radiant power.